We don't usually support this sort of request as ADI would not provide or offer support for the eval software source code. However, we have an available software driver for the AD779x family. This can be also applicable for the AD7798. So you can use this as your reference code. Hope this will help. Kindly refer to the link below: https://wiki.analog.com/resources/tools-software/uc-drivers/renesas/ad7799.